Automatic-block signaling system for electric railways.



S. M. DAY.

- AUTOMATIC BLOCK SIGNALING SYSTEMIFOR ELECTRIC RAILWAYIS.

7 APPLICATION FILED OCT. 8. I908.

Patented Apr. 27, 1915.

3 SHEETS-S H EET 1 INVENTOR V ,y lMw/JLfid/ Ww- ATTORNEY IE NORRIS PETERS c0, PHOTCALITHO. WASHINGTnN, n c

S. M. DAY.

AUTOMATIC BLOCK SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLICATION FILED OCT-8. I908.

1,137,705, Patented Apr. 27, 1915.

. 3 SHEETS-SHEET 2 4 FIGS. 1 F m g IIIIEIIII.

WITNESSES: 75 i INVWTOR A a/zMwyflZfla A ATTORNEY s. M, DAY. I

AUTOMATIC BLOCK SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLICATION FILED OCT- 3 I908.

1,1373% Patented Apr. 27, 1915.

3 SHEETS-SHEET 3. FIG-7 A I I Facia I TR/ENTOR sa /M81 21. Day

YHE NORRIS-FETERS CO4, PHOTC-LlTfIO" WASHINGTON. D, C.

SALISBURY MARCUS DAY, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, A CORPORATION OF NEW YORK.

AUTOMATIC BLOCK-SIGNALING SYSTEM, FOR ELECTRIC RAILWAYS.

Specification of Letters Patent.

Application filed October 8, 1908. Serial No. 456,812.

To all whom it may concern Be it known that I, SALISBURY MARCUS DAY, a citizen of the United States, residing at Rochester, county of Monroe, State of New York, have invented certain new and useful Improvements in Automatic Block- Signaling Systems for Electric Railways, of

which the following is a specification.

My invention relates to improvements in the types of automatic block signaling systems wherein the signals are controlled by a difference of potential across the rails of the block sections. It is applicable to steam or electric railways employing either alternating or direct current for signal control and operation.

Heretofore it has been the practice to endeavor to prevent the false operation of the signal controlling device connected across the rails, by a plurality of frequencies, phases, cross-bonds, and the like; but in all such systems there has been a tendency to false operation under certain abnormal conditions, such as grounded circuits, broken rails, abnormal surges of current supply, etc. My invention obviates this and removes any tendency to false operation.

Briefly my invention consists in employing auxiliary means to prevent the false operation of the signaling devices.

The accompanying diagrammatic drawings will serve to illustrate my invention, in which,

Figure 1 is a diagram illustrating the arrangement in connection with the several parts constituting my system. Fig. 2 is a similar diagram showing modification, and especially adapted for use upon a railway where the power used for propelling the cars differs in character from the signaling power. Figs. 3, 1,5 and 6 are diagrams of variations of arrangement and connection of the auxiliary and main relays. Fig. 7 is a diagram illustrating the employment of an auxiliary and main relay, with the main relay of the eddy phase type. Fig. 8 is a diagram showing a modification where the auxiliary relay serves to control the current of the main relay. Fig. 9 is a diagram which shows a further modification of a plurality of'auxiliary relays controlling the main relay.

Referring to the figures in which like reference numbers and letters are used to designate similar parts :P is a source of current for propelling the cars, which may be either dlrect or alternating, fed to the motor vehicles 4; (Figs. 1 and 2) by supply conductor 1 and returning along the rails 2 and 3 to the source of power current P. The rails are divided into block sections A, B, C, etc, l Il FlgS. 1, 2, 3, 4, 5, 6, 7, and 9, by insulated oints 4; balanced reactance cross-bonds 5 are placed at the ends of the block sections and are connected together at their middle points by conductor 6 for the purpose of making the rails conductively continuous. As is well known, the function of such bonds is to allow the free and unimpeded passage of the power current from block to block while impeding the passage of the signaling current from block to block sufficiently to prevent the signaling devices of one block being operated by the energy fed to adjacent blocks.

In Fig. 8 the block definition is deter mined by the cross-bonds 6 the reactance of the rails performs the function of the reactance of bonds 5 in the other figures. S is a source. of signaling current which, as is well.

Patented Apr. 2'7, 1915. V

known, may or may not differ in character.

from the power current P according to the measure of protection against false operation that is desired. Further protection of the same character may be obtained by a plurality of sources of signaling current differing in character from each other and from the power current. The signaling current is fed to the signaling devices by the conductors 7, 8. Transformers 9, connected to these supply conductors 7, 8, feed signaling energy to the block sections.

In Figs. 1, 2, 3, 4, 5, 6, 8, and 9, the signal controlling relay 10 is of the polyphase induction type with one member 11 connected across the rails of the block sections and another member 12 inductively energized from connections across the source of signaling'energy, the connection of member 11 in Fig. 8, being inductive. The movable member 13 controls, by contact arm 1d and contact 15, the local signal circuit 16 and the signal 17 indicatesin a well knownmanner the presence or absence of trains in the block sections. The movable armature 13 of Fig. 8 has a resistance 18 in circuit as will be fully described. The signal controlling relay 10 of Fig. 7 is of the eddy current disk type.

In Figs. 1, 3, 4, 5, 6, 7, and 9, the prorails.

' figure by employment of additional auxtective relay 19 is of the tractive type. The winding of this relay is shown divided into 7 two parts 20,21. 22 is a contact arm which under normal and safe conditions of the trackway and electrical circuits makes contact with contact 23 and thus permits the signal controlling relay 10, to respond to the signaling energy fed'to the block sections.

In Figs. 2 and 8 the protective relay 19 is of the polyphase induction type with two stationary windings 20 21 and an armature operating a contact arm 22, designed to make contact with contact 23.

In Fig. 9, track winding 11 of the'signal controlling relay is connected directly across the-rails. Track winding 20 of auxiliary relay 19 is inductively connected across the The line windings 12 and 21 of these two relays are connected in multiple across the source of signaling energy. The circuit of'line'winding 12 has'contact 23 and contact arm 22 in series therewith. Additional protection against false operation is obtained in the embodiment shown in this iliary relay 24. The two-windings 25, 26 of this relay are connected together in multiple with the secondary of transformer 9. The energy is fed to the block sectionfrom this secondary in series with contact 27 and contact arm 28 of this auxiliary relay 24.

In these different figures the protective relays are shown variously connected with relation to the signal controlling devices, track circuits and sources of energy. For thepurpose of describing the various methods of connecting these relays and their operation we will use the words track winding to refer to the windings that are controlled by the track circuits, and the Words line winding to describe the windings that are energized directly from the source or sources of energy.

All of the protective relays are designed under normal and safe operating condi-.

tions of the trackway and electrical circuits to bein the deenergized position, and the operation of the system under these conditions would be as though the protective relays were not present.

It will be understood that any types of translating devices may be employed such for example as circuit controlling relays or motor devices operating the signal semaphores directly.

Assume in Fig. 1 that signaling supply wire 8 has become grounded (3 and that one of the Wires connecting track wind ing 11 of the signal controlling relay has become crossed (m) with signahng supply wire 7. It will now be observed that there is a path through track winding 11 for the signaling current, as follows, from conductor 7 through cross as through 7 Winding .11 to rail 3 and then through earth line winding 12 of relay 10 is connected in series with contact arm 22 and back contact 23 of the protective relay 19. Under normal and safe operative conditions relay 19 will not be sufliciently energized to cause it to hold up contact arm22. This can be accomplished either by adjusting the weight of the contact arm 22 or by making the impedance of'windings 20 and 21 high in comparison to the impedance of windings l1 and 12, so that the normal signaling voltages will operate relay 10 but will not send current enough through windings 20 and 21 to actuate relay 19. Under the'dangerous conditions, such as the cross and ground just described, the excessive E. M. F. thus set up will actuate relay 19 to open line winding 12 of relay; 10 and thus cause thisrelay to become de'elnergized and the signal to go to danger. In other words an excessive voltage of any character in either the line or track windings of the signal controlling relay will actuate relay 19 and thus cause the signal to go to danger.

For the purpose of describing the operation of the embodiment of my invention, illustrated by Fig. 2, assume the power current from alternator P has a frequency of 25 cycles and that the frequency of the current from alternator S is 60 cycles. As is well known, relay 10, which has its line winding 12 inductively energized from connections across the 60 cycles signaling energy, will be responsive only to a difference of 60 cycle potential across the rails and relay 19 whose line winding 21 is inductively energized from connections across the source of 25 cycle current, will be responsive only toia difference of 25 cycle potential across the rails. Under normal and safe operating conditions there will be no difference of power current potential across the rails. Relay 19 will, therefore,

be normally deenergized and the circuit of line winding 12 of relay 10 will be closed through contact arm 22 and contact 23 of.

relay 19 If one of the rails should become electrically broken, as at z in block B, it is apparent that there will be a difference of 25 cycle power potential across the rails of block B. When there is such a difference of power current potential relay 19 will become energized to open the circuit of line winding 12 of relay 10 and cause this relay 10 to drop its armature and the signal to go to danger. V a o The operation of Fig. 3 is similar to that of Fig. 1 except that the protective relay 19 opens the circuit of track winding 11 of relay 10. The operation of Fig. 4 is also similar to the operation of Fig. l-except that both the track and the line windings 11 and 12 of relay 10 are controlled by the protective relay 19. The operation of Fig.

5 is also similar to the operation of Fig. 1 except that track winding 11 of relay 10, and track winding 20 of relay 19, are connected together in series across the rails. In

this embodiment the protective relay 19 would be more sensitive to an excessive rise 1n voltage, or to the presence in the signaling circuits of a difierence of potential other .than that of the signaling current. Fig. 6

is similar to Fig. 3 except that line windings 12 of relay 10, and 21 of relay 19, are con nected together in series across the source of signaling energy. This embodiment is particularly adapted for protection. against sudden surges in the signaling voltage. The

operation of Fig. 7 is also similar to the operation of Fig. 1 except that in this embodiment a one winding signal controlling relay is used. The energy for this winding is connected in series with contact arm 22 and contact 23, across the rails. The windings of protective relay 19 are also connected across the rails.

The operation of the embodiment shown in Fig. 8 is similar to Fig. 1 in its connections but different from Fig. 1 in that the armature of the signal controllingrelay is controlled by the protective relay as follows :When protective relay 19 is deenergized the armature 13 of the signal controlling relay will be short circuited through contact arm 22 and contact 23 of the protec tive relay. Under these conditions the relay 10 will have its maximum torque and if no train is present the local circuit 16 will be closed and signal 17 at clear. Under dangerous conditions, such as described, relay 19 will be energized to cut resistance 18 into the armature circuit of relay 10. When this occurs relay 10 will have a minimum torque, its armature will drop and the signal 17 will go to danger.

The operation of the embodiment, illustrated by Fig. 9, is as follows: Under normal and safe conditions of the trackway and circuits, the protective relays 19 and 24 will not be energized sufficiently to hold up the contact arms 22 and 28. The line winding 12 of relay 10, which is in series through a back contact of relay 19, will normally be energized, also the secondary of transformer 9 will normally feed energy to the block' sections through back contact 27' of relay 24. As in the other figures, if any excessive or foreign diiferences of potential occur in any of the various elements of the signaling system, one or the other or both of will be responsive only to excessive alternating current in the rails. I

I do not wish to be understood as in any wise limiting myself to the particular construction or connections shown in the figures as it will be apparent to an engineer that there will be a great many possible variations of my invention.

Having thus described my invention I claim:

1. In a signaling system for railways, a track-way divided into block sections, means for impressing a difference of alternating signaling current potential across the rails of each block section, signal controlling means controlled by the presence of trains in the block sections, auxiliary means controlling the operation of said signal controlling means said auxiliary means adapted to be responsive to a difference of signaling current potential across the rails, other than a normal dilference of signaling current potential and irresponsive to said normal signaling current potential.

'2. In a block signaling system for rail ways, a source of signaling current for supplying energy to the blocks,signal controlling relays, one for each block having one member connected across the rails of said I block, another memberconnected across the source of signaling energy, an auxlliary re that is connected across the source of mgnaling energy.

3. In a block signaling system for railways, a trackway divided into block sections, a source of signaling current for supplying energy to the block sections, signal controlling relays, one for each block section, each having one member connected across the rails of said block section, and another member connected across the source of signaling energy, auxiliary relays each having two members, respectively connected in multiple with the two members of a signal controlling relay and controlling the member of the signal controlling relay that is connected across, the rails.

4. In a block signaling system for railways, a source of signaling current for supplying energy to the blocks, signal controlling relays, one for each block, each having one member connected across the rails, and

- ing two members, respectively connected in multiple with the two members of a signal controlling relay and controlling both members of the signal controlling relay.

. 5. In a system of automatic block signaling for railways, a signal controlling device responsive to a difference of electrical potential across the rails of the block sections, means for controlling the operation of the signal controlling device, responsive to the signaling energy only when said signaling energy rises to an abnormal or dangerous potential.

- 6. In a block signaling system for railways, a source of alternating signaling current for supplying energy to the blocks, a signal controlling relay responsive to eddy currents generated in amoving body by energy fed to the blocks, an auxiliary relay of the tractive type connected in multiple with the signal controlling relay, and controlling said signal controlling relay through a back contact of the tractive relay, while leaving the tractive relay in circuit point.

'7. In a block signaling system for railways, a source of signalingenergy, a relay controlling said source of energy adapted to be responsive only to the presenceof signaling current of excessive voltage in said source of energy, and irresponsive to the normal signaling current.

'8. In a block signaling system for railways, a source of signaling energy, signal controlling relays, one for eachblock section, auxiliary relays, one controlling each signal controlling relay, said auxiliary relays responsive only to signaling currents of excessive difference of potential in the track- "way or electrical circuits, and irresponsive to the normal signaling currents.

each of which is connected in multiple with one of the windings of said signal controlling relays.

10. In. a signaling system of the type described, signal controlling relays, each having a plurality of windings, auxiliary relays, each having a plurality of windings, one of said windings connected in multiple with a winding of said signal controlling relay, said auxiliary relays being irresponsive to the normal signaling current and only responding to an excessive signaling potential.

11. In a signaling system of the type described, signal controlling relays, each having a plurality of windings, auxiliary relays, each having a plurality of windings, one of said windings of the auxiliary relays connected in multiple with one of the windings of the signal controlling relays, said auxiliary relays being irresponsive to the normal signaling current and only responding to an excessive signaling potential.

'12. In a signaling system of the type described, signal controlling relays, each having a plurality of windings, auxiliary relays, each having a plurality of windingsone of the windings of each auxiliary relay connected in multiple with a winding of a signal controlling relay, said auxiliary relays being irresponsive to the normal signaling current and only responding to an excessive signaling potential. I

In testimony whereof, I afiix my signature in the presence of two witnesses.

SALISBURY MARCUS DAY. Witnesses: 7

Ross CAMPBELL, S. C. SARGENT.

'cbpies ofthi's patent may be obtained forfive centseach, by addressing the Commissioner of Patents, Washington, 20.0. I 

